
// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2017 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#ifndef EIGEN_ARCH_CONJ_HELPER_H
#define EIGEN_ARCH_CONJ_HELPER_H

#define EIGEN_MAKE_CONJ_HELPER_CPLX_REAL(PACKET_CPLX, PACKET_REAL)                                                     \
	template<>                                                                                                         \
	struct conj_helper<PACKET_REAL, PACKET_CPLX, false, false>                                                         \
	{                                                                                                                  \
		EIGEN_STRONG_INLINE PACKET_CPLX pmadd(const PACKET_REAL& x, const PACKET_CPLX& y, const PACKET_CPLX& c) const  \
		{                                                                                                              \
			return padd(c, this->pmul(x, y));                                                                          \
		}                                                                                                              \
		EIGEN_STRONG_INLINE PACKET_CPLX pmul(const PACKET_REAL& x, const PACKET_CPLX& y) const                         \
		{                                                                                                              \
			return PACKET_CPLX(Eigen::internal::pmul<PACKET_REAL>(x, y.v));                                            \
		}                                                                                                              \
	};                                                                                                                 \
                                                                                                                       \
	template<>                                                                                                         \
	struct conj_helper<PACKET_CPLX, PACKET_REAL, false, false>                                                         \
	{                                                                                                                  \
		EIGEN_STRONG_INLINE PACKET_CPLX pmadd(const PACKET_CPLX& x, const PACKET_REAL& y, const PACKET_CPLX& c) const  \
		{                                                                                                              \
			return padd(c, this->pmul(x, y));                                                                          \
		}                                                                                                              \
		EIGEN_STRONG_INLINE PACKET_CPLX pmul(const PACKET_CPLX& x, const PACKET_REAL& y) const                         \
		{                                                                                                              \
			return PACKET_CPLX(Eigen::internal::pmul<PACKET_REAL>(x.v, y));                                            \
		}                                                                                                              \
	};

namespace Eigen {
namespace internal {

template<bool Conjugate>
struct conj_if;

template<>
struct conj_if<true>
{
	template<typename T>
	EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE T operator()(const T& x) const
	{
		return numext::conj(x);
	}
	template<typename T>
	EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE T pconj(const T& x) const
	{
		return internal::pconj(x);
	}
};

template<>
struct conj_if<false>
{
	template<typename T>
	EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const T& operator()(const T& x) const
	{
		return x;
	}
	template<typename T>
	EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const T& pconj(const T& x) const
	{
		return x;
	}
};

// Generic Implementation, assume scalars since the packet-version is
// specialized below.
template<typename LhsType, typename RhsType, bool ConjLhs, bool ConjRhs>
struct conj_helper
{
	typedef typename ScalarBinaryOpTraits<LhsType, RhsType>::ReturnType ResultType;

	EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE ResultType pmadd(const LhsType& x,
														   const RhsType& y,
														   const ResultType& c) const
	{
		return this->pmul(x, y) + c;
	}

	EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE ResultType pmul(const LhsType& x, const RhsType& y) const
	{
		return conj_if<ConjLhs>()(x) * conj_if<ConjRhs>()(y);
	}
};

template<typename LhsScalar, typename RhsScalar>
struct conj_helper<LhsScalar, RhsScalar, true, true>
{
	typedef typename ScalarBinaryOpTraits<LhsScalar, RhsScalar>::ReturnType ResultType;

	EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE ResultType pmadd(const LhsScalar& x,
														   const RhsScalar& y,
														   const ResultType& c) const
	{
		return this->pmul(x, y) + c;
	}

	// We save a conjuation by using the identity conj(a)*conj(b) = conj(a*b).
	EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE ResultType pmul(const LhsScalar& x, const RhsScalar& y) const
	{
		return numext::conj(x * y);
	}
};

// Implementation with equal type, use packet operations.
template<typename Packet, bool ConjLhs, bool ConjRhs>
struct conj_helper<Packet, Packet, ConjLhs, ConjRhs>
{
	typedef Packet ResultType;
	EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet pmadd(const Packet& x, const Packet& y, const Packet& c) const
	{
		return Eigen::internal::pmadd(conj_if<ConjLhs>().pconj(x), conj_if<ConjRhs>().pconj(y), c);
	}

	EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet pmul(const Packet& x, const Packet& y) const
	{
		return Eigen::internal::pmul(conj_if<ConjLhs>().pconj(x), conj_if<ConjRhs>().pconj(y));
	}
};

template<typename Packet>
struct conj_helper<Packet, Packet, true, true>
{
	typedef Packet ResultType;

	EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet pmadd(const Packet& x, const Packet& y, const Packet& c) const
	{
		return Eigen::internal::pmadd(pconj(x), pconj(y), c);
	}
	// We save a conjuation by using the identity conj(a)*conj(b) = conj(a*b).
	EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Packet pmul(const Packet& x, const Packet& y) const
	{
		return pconj(Eigen::internal::pmul(x, y));
	}
};

} // namespace internal
} // namespace Eigen

#endif // EIGEN_ARCH_CONJ_HELPER_H
